diff --git a/mseedpeek/mseedpeek.py b/mseedpeek/mseedpeek.py
index 9f76942a4f36e86fcd132bd889ee29b41e524cb9..5055be83e3d4e815a605be5850689d90d2e44c71 100644
--- a/mseedpeek/mseedpeek.py
+++ b/mseedpeek/mseedpeek.py
@@ -895,8 +895,11 @@ class MainWindow(QWidget):
                                 if odd_size:
                                     warn = ("ERROR: File size is not an "
                                             " integer number of block size (" +
-                                            str(blksize) + "). \n\t File: " +
-                                            fullname)
+                                            str(blksize) + ").")
+                                    warn += " Header reading may not work."
+                                    warn += " To fix variable record length"
+                                    warn += ", use fixhdr."
+                                    warn += f"\n\t File: {fullname}"
                                     print(warn)
                                     rw_error += 1
                                     continue